cut down vs scythe

cut down is not a noun while scythe is a noun.

Word	Noun	Adjective	Verb	Adverb
cut down	No	No	Yes	No
scythe	Yes	No	Yes	No

As verbs, scythe is a hyponym of cut down; that is, scythe is a word with a more specific, narrower meaning than cut down:

cut down (noun)	scythe (noun)
	an edge tool for cutting grass; has a long handle that must be held with both hands and a curved blade that moves parallel to the ground

cut down (verb)	scythe (verb)
cut down on; make a reduction in	cut with a scythe
intercept (a player)
cause to come or go down
cut with a blade or mower
cause to fall by or as if by delivering a blow
cut with sweeping strokes; as with an ax or machete